1. Field of the invention
This invention relates to a cutting device according to the shearing principle with two circular blades, one blade of which in the form of an elastic disc can be displaced on a bracket and is pressed by a pressure element engaged by means of a lever with its cutting edge against the cutting edge of the other blade.
2. Discussion of the Prior Art
Such a cutting device is known from U.S. Pat. No. 3,380,330. It serves to cut the strip material longitudinally. In the known cutting device the lever is forked and presses on one side centrally onto the bearing of the elastic disc. The bearing is supported on its opposing side by a pressure spring. While the lever presses the elastic disc towards the other circular blade, the pressure spring applies force onto the disc in the opposite direction. As the forked lever acts centrally on the bearing of the elastic disc, the disc is supported by its cutting area on the opposite blade, the reaction force in the cutting area of the two blades produces a moment which acts on the bearing of the elastic disc. As long as the friction between the bearing of the elastic disc and the bracket is not negligibly low in axial direction, this acts deceivingly on the plant force of the elastic disc to be adjusted at the pressure element at the opposing blade.
Still more serious is the effect that in the case of the opposing blade being struck, for example, a possible clamping moment working between the bearing and bracket is reduced in removing the opposing blade from the elastic disc, so that the elastic disc is further shifted by the lever towards the opposing blade. If the cutting edge of the longitudinal blade then subsequently reassumes its precalculated position, a greater reaction force becomes effective on the elastic disc and thereby a greater clamping moment becomes effective between the bearing and the bracket. However, if the cutting edge of the opposing blade as a consequence of the opposite blade being struck moves in the direction of the elastic disc, the clamping moment will be increased due to the increased reaction force. The bearing of the elastic disc reacts differently depending on how the opposing blade is struck.
It is an object of this invention, therefore, to provide a cutting device of the above-mentioned type, with which the plant force of the elastic disc can be exactly adjusted at the opposing blade and in which axial impact on the cutting edge of the opposing blade cannot cause the elastic disc to shift axially on the bracket.